Peptides and nanoparticle formulations thereof

Abstract

The present invention relates to peptides, methods for production of the same, nanoparticle formulations of the same and the use of these new peptides and nanoparticle formulations as inhibitors of protein-protein interactions, in particular for application in the treatment of diseases associated with overexpression of the RAN gene.

1 . A method for the preparation of a peptide inhibitor of the RanGDP-RCC1 protein/protein interaction comprising the steps of:
 i) identifying segments of the Ran protein sequence (SEQ ID NO: 1) predicted to interact with RCC1 in the formation or stabilisation of the RanGDP-RCC1 complex; and   ii) preparing a 6 to 25 amino acid peptide with a sequence comprising a contiguous sequence of at least 6 amino acids corresponding to a portion of one of the segments of Ran identified in step i);   wherein the peptide optionally has a cysteine residue not present in the corresponding segment of Ran at its N-terminus, and wherein, not counting the optional cysteine residue at the N-terminus, the peptide has at least 80% homology with a portion of one of the segments of Ran identified in step i) or has not more than 2 point deletions or mutations relative to a portion of one of the segments of Ran identified in step i).   
     
     
         2 . A method according to  claim 1 , wherein the segment of the Ran protein predicted to interact with RCC1 in the formation or stabilisation of the RanGDP-RCC1 complex is selected from SEQ ID NO: 2; SEQ ID NO: 3; or SEQ ID NO: 4. 
     
     
         3 . A method according to  claim 1 , wherein the peptide inhibitor of RanGDP-RCC1 protein/protein interaction produced has 90% homology, optionally 100% homology, with a portion of the segment of the Ran protein predicted to interact with RCC1 in the formation or stabilisation of the RanGDP-RCC1 complex. 
     
     
         4 . A method according to  claim 1 , wherein the peptide is a 8 to 20 amino acid peptide, or a 1 to 15 amino acid peptide. 
     
     
         5 . A peptide consisting of from 6 to 25 amino acids comprising the amino acid sequence
   (X) m —Y
   
       wherein: X=Cys; m=0 or 1; and Y is an amino acid sequence comprising a contiguous sequence of 6 amino acids that is present in SEQ ID NO: 2; SEQ ID NO: 3; or SEQ ID NO: 4 further wherein a) Y is sequence having at least 80% homology to a portion of SEQ ID NO: 2, 3, or 4 containing the same number of amino acids; or b) Y is a sequence corresponding to a portion of SEQ ID NO: 2, 3, or 4 having not more than 2 point deletions or mutations; or a pharmaceutically acceptable form thereof. 
     
     
         6 . A peptide according to  claim 5  wherein Y is 90% or 100% homologous to a portion of SEQ ID NO: 2, 3, or 4 containing the same number of amino acids. 
     
     
         7 . A peptide according to  claim 5  wherein the Y is an amino acid sequence comprising a contiguous sequence of 6 amino acids, optionally a contiguous sequence of 8 amino acids, optionally a contiguous sequence of 10 or more amino acids that is present in SEQ ID NO: 2. 
     
     
         8 . A peptide according to  claim 5  wherein the integer m is 1. 
     
     
         9 ) A peptide according to  claim 5  wherein the group Y comprises the contiguous sequence Ala-Gln-Gly-Glu (AQGE). 
     
     
         10 . A peptide according to  claim 5  having the structure SEQ ID NO: 5, SEQ ID NO: 6 or SEQ ID NO: 7. 
     
     
         11 . An inhibitor of the RanGDP-RCC1 protein interaction for use in medicine. 
     
     
         12 . Inhibitor for use according to  claim 11 , wherein the inhibitor is a competitive inhibitor. 
     
     
         13 . Inhibitor for use according to  claim 11 , wherein the inhibitor is a peptide according to any of  claims 5  to  10  or is the product of a method according to any of  claims 1  to  4 . 
     
     
         14 . Inhibitor for use according to  claim 11 , for the treatment of cancer. 
     
     
         15 . Inhibitor for use according to  claim 14  wherein the cancer is selected from the group comprising breast, lung, prostate, ovarian, blood, brain and renal cancers. 
     
     
         16 . A nanoparticle formulation of an inhibitor for use according to  claim 11 . 
     
     
         17 . A nanoparticle formulation according to  claim 16  wherein the nanoparticle comprises poly(lactic-co-glycolic acid) (PLGA). 
     
     
         18 . A nanoparticle formulation according to  claim 17  wherein the nanoparticle comprises, in addition to the inhibitor for use, a poly(lactic-co-glycolic acid)/polyethylene (PEG) block copolymer, optionally wherein the content of PEG relative to PLGA is from 1% to 15%. 
     
     
         19 . A nanoparticle formulation according to  claim 16  wherein the nanoparticle has a mean diameter of from 100 nm to 400 nm. 
     
     
         20 . Use of a peptide according to  claim 5  or the product of a method of  claim 1  for the manufacture of a medicament, optionally wherein the medicament is for the treatment of cancer. 
     
     
         21 . A method of treatment for a patient in need thereof comprising the step of administering an inhibitor of the RanGDP-RCC1 protein-protein interaction, optionally wherein the patient has cancer.